c © World Scientic Publishing Company FEASIBILITY STUDIES OF THE THREE-DIMENSIONAL DETECTOR FOR SOFT X-RAY EMISSION SPECTROSCOPY

A time-resolving two-dimensional position-sensitive detector was applied to soft X-ray emission spectroscopy (SXES) and its feasibility was successfully studied by using synchrotron radiation. A soft X-ray emission spectrum synchronously acquired with bunch signal of the storage ring has elucidated that a threefold higher signal-to-noise ratio could at least be achieved. By adopting a pump{probe technique to SXES, we have preliminarily studied the eect of the electron{hole plasma (EHP) on the Si 2p soft X-ray emitting processes of Si crystal. A meaningful change in the excitation curve for the elastic scattering yields near the 2p thresholds was found to be probably due to the many-body interactions caused by the EHP. 1